The invention relates to a material level checking apparatus and method for a rotating vessel, and is more particularly concerned with a material level checking apparatus and method for a rotary calcination furnace.
When material is fed through a rotating vessel, such as a rotary calcination furnace, the material bed inside the rotating vessel will tend to climb upwardly along the ascending side of the vessel, until it reaches its normal angle for repose, and will then tumble toward the bottom of the rotating vessel by gravity. This phenomenon is known as "folding" of the material. Due to "folding", the level of material within a rotating vessel is difficult to measure. This difficulty in effectively measuring the level of material can result in excessive feed flow further resulting in backspill to the inlet of the rotating vessel and possible rupture of the ceiling means and loss of feed material.